Randomized controlled trials on prevention, diagnosis, and treatment of diabetes in African countries - a systematic review

Angelika Sandholzer-Yilmaz, Susanne Unverzagt, Thomas Frese, Eric Kroeber

Keywords: Diabetes mellitus, Africa, systematic review, randomized-controlled trial

The epidemiological transition from infectious to chronic diseases leads to novel challenges in African health systems. The prevalence of diabetes mellitus (DM) is increasing dramatically. Undiagnosed and undertreated DM leads to numerous complications including end-organ damage and death.

Research questions:
Our objectives were to collect the best locally generated evidence on DM interventions, identify knowledge gaps, and determine underexplored research areas.

Design: A systematic review and meta-analysis of randomized controlled trials (RCTs).
Participants and setting: African patients in primary, secondary and tertiary prevention, diagnosis and treatment DM type 1 (DM1), type 2 (DM2) and gestational DM (GDM).
Outcome: All-cause mortality, glycemic control, complications, quality of life, hospital admission, treatment adherance and costs.
Data sources: Articles published in MEDLINE Ovid, CENTRAL, CINAHL, African Journals Online and African Index Medicus and the International Clinical Trials Registry Platform in English language until October 2020.

Out of 3584 identified publications, we included 60 eligible studies conducted in 15 countries 75% were conducted in urban health care settings, including 10,112 participants. We included eight studies on DM1, six on GDM, two on pre-DM, 37 on mainly DM2 including seven on DM related complications. The design of the studied interventions was heterogeneous with a focus on educational strategies. The other studies investigated the efficacy of nutritional strategies including food supplementations, pharmacological strategies and strategies to enhance physical activities. Seven studies included interventions on DM-related complications.

Research activities increased in recent years. Available evidence is still not representative for all African countries and rural areas. We detected a lack of evidence in primary health care and locally implemented pharmacolocial Interventions. The identified studies offer a variety of effective approaches as a basis for local guidelines in DM care adjusted to regional circumstances.

Points for discussion:
Implication for further locally feasible research

Implications for improving diabetes control in Africa